A majority of evolutionary biologists believe that we now can envision our biological predecessors--not the first, but nearly the first, living beings on Earth. This book is about these vanished forebears. The era between the first rudimentary life on Earth and the appearance of more complex beings is called the RNA world. It is RNA (ribonucleic acid) long believed to be a mere biologic copier and messenger, that offers a glimpse into our ancient predecessors. To describe early RNA creatures, here called "ribocytes" or RNA cells, the author uses basics of molecular biology. He reviews our current understanding of the tree of life, examines the structure of RNA itself, explains the operation of the genetic code, and more. Courting controversy among those who question the role of ribocytes -- citing the chemical fragility of RNA and the uncertainty about the origin of an RNA synthetic apparatus -- he offers a vision of early life on Earth.

"A Subject Collection from Cold Spring Harbor Perspectives in Biology."

RNA molecules could function as catalysts. --

A dual biography of Joan Steitz and Jennifer Doudna, two women who combined successful home lives with successful careers in science.

Recent studies on the activities of RNA in the cell have revolutionized our understanding of the many roles played by this molecule. The first two editions of The RNA World(1993, 1999) shed light on the pre–biotic era dominated by this versatile molecule, and provided an overview of the state of RNA research at the time. The new third edition of The RNA Worldupdates this perspective, describing the vast array of newly discovered roles for RNA in the modern world. The updated original chapters are supplemented with new chapters on RNA–protein complexes, snRNPs and snoRNPs, telomerase RNA, RNAi, microRNAs, noncoding RNA, and many other subjects. This book is essential reading for anyone interested in the biology of nucleic acids and gene regulation and a valuable resource for teaching these concepts.

This volume reviews our understanding of two RNA worlds: the primordial RNA world before DNA, in which RNA was both information store and biocatalyst; and the contemporary RNA world, in which mRNA, tRNA, rRNA, siRNA, miRNA, and a host of other RNAs operate.